Electrolysis of cast iron?

I've got an idea for mounting a folding extension table off the back of my table saw which starts with bolting an aluminum angle to the cast iron top. Do I need to worry about electrolysis between the aluminum and the cast iron?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I don't think so. First, for galvanic corrosion to take place, there has to be the prescence of an electrolyte, usually water. Second, there's not a large potential difference between cast iron and aluminum alloys. Even if it did happen somehow, since aluminum is less noble than cast iron, the aluminum (aluminium for our friends across the pond) angle would be the anode and would sacrafice itself, so the table saw top would be protected.
todd
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

For ordinary thicknesses, ok for years. Environment matters, eg. if near ocean, might be bad if the parts are thin. In dry area, no problem.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Roy Smith wrote:

Roy...
I've been using the same aluminum [aluminium] insert in my cast iron table top since 1975 and haven't detected any ill effects. It's probably something not much worth worrying about.
I recently added an outfeed table to my saw - also starting by attaching an aluminum angle - that you can look over at <http://www.iedu.com/DeSoto/outfeed.html . It seems to be surviving fairly well (and will probably outlast me!)
--
Morris Dovey
DeSoto Solar
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Aluminium extrusion is often anodised, which is some of the best electrolytic protection you could get.
As to the rest, then if it's going to get wet, then you should worry (there are primers to deal with this). For a saw part in a normal workshop though, it's no problem.
--
Smert' spamionam

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No. But if still worried, use a plastic shim.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

the big offender is aluminum to copper.
if you're worried about it, slip a sheet of paper between.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.